The present invention relates to a process cartridge and an electrophotographic image forming apparatus.
Here, the electrophotographic image forming apparatus forms an image on a recording material through an electrophotographic image formation type. Examples of electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer or the like), a facsimile machine and a word processor.
The above-described process cartridge contains as a unit an electrophotographic photosensitive member and a charging means, a developing means or a cleaning means in the form of may cartridge which is detachably mountable to a main assembly of an image forming apparatus. The process cartridge may contain an electrophotographic photosensitive member and at least one of a charging means, a developing means and a cleaning means in the form of a cartridge which is detachably mountably to a main assembly of an image forming apparatus. The process cartridge may contain an electrophotographic photosensitive member and at least developing means in the form of a cartridge which is detachably mountably to a main assembly of an image forming apparatus.
With process cartridge type, the servicing or maintenance operations can be in effect carried out by the users, so that the operativity is significantly improved, and therefore, the process cartridge type is widely used in the electrophotographic field.
As shown in FIG. 23, the process cartridge 45 comprises a developing device frame 43 supporting a developing roller 18 and a toner accommodating container 46, which are welded with each other by ultrasonic welding. To the developing unit, a cleaning frame 47 which supports a photosensitive drum 11, a charging roller 12 and a cleaning blade 14, is coupled by a pin 49. A compression coil spring 42 is provided between the cleaner frame 47 and developing device frame 43. By this, the photosensitive drum 11 and the developing roller 18 are urged toward each other with spacer rollers therebetween.
In the electrophotographic image forming apparatus of the process cartridge type, the demand is for a large capacity developer (toner) accommodating container and a large removed toner container to extend the time period until the necessity of exchange of the process cartridge.
When the capacity of the developer accommodating container is increased, the weight of the developer increases correspondingly. Therefore, the force imparted to the developing container is also increased with the result of small deformation. This may bring about deterioration of a positioning accuracy between the developing roller end photosensitive drum.
The present invention is directed to a solution to the problem.
Accordingly, it is a principal object of the present invention to provide a process cartridge and an electrophotographic image forming apparatus wherein an image quality is stabilized even if an accommodation capacity of the developer (toner) is increased.
It is a further object of the present invention to provide a process cartridge positional accuracy electrophotographic image forming apparatus in which the positional accuracy between the electrophotographic photosensitive drum and the developing member is improved. It is a further object of the present invention to provide a process cartridge and an electrophotographic image forming apparatus in which an elastic force can be provided between the electrophotographic photosensitive drum and the developing member with a simple structure.
According to an aspect of the present invention, there is provided a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus. The process cartridge comprises: a drum frame for supporting an electrophotographic photosensitive drum and a developing member for developing an electrostatic latent image formed on the electrophotographic photosensitive member; and a developing frame supporting the developing member. The developing frame is provided at a longitudinal end thereof with a projected portion which is projected in a longitudinal direction of the developing member and which is engaged with a guide member. The projected portion is movable along the guide member toward the drum frame, and the developing frame is swingably connected with the drum frame at the other longitudinal end. The developing member is supported on the developing frame for movement in a direction crossing with the longitudinal direction. The cartridge further includes an elastic member for urging the projected portion along the guide portion toward the drum frame.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.